Direct Synthesis of Bienzyme-like Carbide-derived Carbons via Mild Electrochemical Oxidation of Ti 3AlC 2 MAX / 生物医学与环境科学（英文）

Objective@#To develop effective alternatives to natural enzymes, it is crucial to develop nanozymes that are economical, resource efficient, and environmentally conscious. Carbon nanomaterials that have enzyme-like activities have been extensively developed as substitutes for traditional enzymes.@*Methods@#Carbide-derived carbons (CDCs) were directly synthesized via a one-step electrochemical method from a MAX precursor using an ammonium bifluoride electrolyte at ambient conditions. The CDCs were characterized by systematic techniques.@*Results@#CDCs showed bienzyme-like activities similar to that of peroxidase and superoxide dismutase. We systematically studied the dependence of CDC enzyme-like activity on different electrolytes and electrolysis times to confirm activity dependence on CDC content. Additionally, the synthesis mechanism and CDC applicability were elaborated and demonstrated, respectively.@*Conclusion@#The demonstrated synthesis strategy eliminates tedious intercalation and delamination centrifugation steps and avoids using high concentrations of HF, high temperatures, and halogen gases. This study paves the way for designing two-dimensional material-based nanocatalysts for nanoenzyme and other applications.

Analysis of dental caries and the impact factors of caries in children aged 3-5 years old in Changdu, Xizang / 华西口腔医学杂志

OBJECTIVES@#To investigate caries status and its impact factors in preschool children in plateau and to provide reference for caries prevention in highlands.@*METHODS@#Examination of caries was performed on 1 597 children aged 3-5 years old in 11 kindergartens in Changdu, Xizang, in accordance with the 4th National Oral Health Survey standards and methods. Their parents were surveyed with the questionnaire regarding oral hygiene habit and consciousness about oral health and related factors. All the data were collected and analyzed.@*RESULTS@#The prevalence of caries among children aged 3-5 years old in Changdu was 52.85%, with dmft index of 2.44. The caries rate and dmft of children aged 3 years old were lower than those of children aged 4 and 5 years old (@*CONCLUSIONS@#The prevalence of ca-ries in children aged 3-5 years old in Changdu increases with aging. Good oral hygiene and eating habits and regular oral examination can reduce the rate of caries.

Photothermal Effect-based Cytotoxic Ability of Melanin from Shells to Heal Wounds Infected with Drug-resistant Bacteria / 生物医学与环境科学（英文）

Objective@#Owing to antibiotic abuse and the subsequent development of antibiotic resistance, bacterial infection has become one of the most persistent unresolved problems. New antibacterial agents, especially those that are environmental-friendly, are urgently needed.@*Methods@#Melanin extracted by filtration centrifugation and acid and proteolytic hydrolysis was characterized using UV, FTIR, TEM, and XPS. Photothermal conversion was calculated, and the bacteriostatic effects, and , were assessed by plate counting and ratios (%) of wound areas.@*Results@#Natural melanin hydrolyzed by trypsin had good photothermal conversion effects, which resulted in superior bacteriostatic activities. The extracted melanin along with laser NIR irradiation at 808 nm promoted the healing of wounds infected by drug-resistant bacteria and was biocompatible according to toxicity tests and .@*Conclusion@#The present findings indicated a safe and efficient method of developing natural antibacterial agents.

Drug resistance and pathogenic spectrum of patients coinfected with nontuberculous mycobacteria and human-immunodeficiency virus in Chengdu, China / 中华医学杂志(英文版)

Background@#Human-immunodeficiency virus (HIV) infection is increasing worldwide and nontuberculous mycobacteria (NTM) is an established microbiologic cause of pulmonary disease, lymphadenitis, and disseminated disease in cases of advanced immune suppression. Data on patients coinfected with HIV and NTM are limited. Thus, this study aimed to analyze the clinical characteristics, drug resistance, and pathogen spectrum of patients coinfected with both HIV and NTM in the Chengdu area of China.@*Methods@#Data of 59 patients coinfected with both HIV and NTM collected from the Public Health Clinical Center of Chengdu, between January 2014 and December 2018, were analyzed. NTM drug sensitivity testing was performed using the microporous plate ratio method. Data were analyzed using SPSS 19.0, and the change in drug resistance rate was analyzed using the chi-square (χ2) test.@*Results@#Seven species/complex of NTM were identified from patients coinfected with HIV and NTM in this study, with Mycobacterium avium–intracellulare complex (52.5%) and M. kansasii (27.1%) as the predominant species. Male patients were more affected 50/59 (84.7%); the mean age of the 59 cases was 45 years. The clinical characteristics mainly included anemia (86.4%), cough and expectoration (79.7%). The baseline CD4 count was <50 cells/μL (84.7%). Patients were mainly in advanced acquired immunodeficiency syndrome (AIDS) stage. Chest imaging mainly showed patchy shadows (42.4%) and nodules (32.2%), with various degrees of AIDS-defining diseases. The drug resistance of NTM was severe, and the rate of isoniazid resistance (100.0%) was the highest, followed by rifampicin (94.9%), streptomycin (94.9%), ofloxacin (93.2%), and others. Ethambutol (52.5%) and clarithromycin (33.9%) were relatively low. No significant difference was found in the drug resistance rate of NTM strain against nine antituberculosis drugs in 5 years (P > 0.05).@*Conclusions@#The immune level of patients coinfected with HIV and NTM is low in advanced AIDS stage; more male are affected in patients who are mainly infected with MAC and M. kansasii and with serious drug resistance. The drug resistance rate of ethambutol and clarithromycin is relatively low.

Drug resistance and pathogenic spectrum of patients coinfected with nontuberculous mycobacteria and human-immunodeficiency virus in Chengdu, China / 中华医学杂志(英文版)

BACKGROUND@#Human-immunodeficiency virus (HIV) infection is increasing worldwide and nontuberculous mycobacteria (NTM) is an established microbiologic cause of pulmonary disease, lymphadenitis, and disseminated disease in cases of advanced immune suppression. Data on patients coinfected with HIV and NTM are limited. Thus, this study aimed to analyze the clinical characteristics, drug resistance, and pathogen spectrum of patients coinfected with both HIV and NTM in the Chengdu area of China.@*METHODS@#Data of 59 patients coinfected with both HIV and NTM collected from the Public Health Clinical Center of Chengdu, between January 2014 and December 2018, were analyzed. NTM drug sensitivity testing was performed using the microporous plate ratio method. Data were analyzed using SPSS 19.0, and the change in drug resistance rate was analyzed using the chi-square (χ) test.@*RESULTS@#Seven species/complex of NTM were identified from patients coinfected with HIV and NTM in this study, with Mycobacterium avium-intracellulare complex (52.5%) and M. kansasii (27.1%) as the predominant species. Male patients were more affected 50/59 (84.7%); the mean age of the 59 cases was 45 years. The clinical characteristics mainly included anemia (86.4%), cough and expectoration (79.7%). The baseline CD4 count was 0.05).@*CONCLUSIONS@#The immune level of patients coinfected with HIV and NTM is low in advanced AIDS stage; more male are affected in patients who are mainly infected with MAC and M. kansasii and with serious drug resistance. The drug resistance rate of ethambutol and clarithromycin is relatively low.

The mechanisms and treatments of muscular pathological changes in immobilization-induced joint contracture: A literature review / 中华创伤杂志(英文版)

The clinical treatment of joint contracture due to immobilization remains difficult. The pathological changes of muscle tissue caused by immobilization-induced joint contracture include disuse skeletal muscle atrophy and skeletal muscle tissue fibrosis. The proteolytic pathways involved in disuse muscle atrophy include the ubiquitin-proteasome-dependent pathway, caspase system pathway, matrix metalloproteinase pathway, Ca-dependent pathway and autophagy-lysosomal pathway. The important biological processes involved in skeletal muscle fibrosis include intermuscular connective tissue thickening caused by transforming growth factor-β1 and an anaerobic environment within the skeletal muscle leading to the induction of hypoxia-inducible factor-1α. This article reviews the progress made in understanding the pathological processes involved in immobilization-induced muscle contracture and the currently available treatments. Understanding the mechanisms involved in immobilization-induced contracture of muscle tissue should facilitate the development of more effective treatment measures for the different mechanisms in the future.

Recent progress in the study of reduction-sensitive drug carriers / 药学学报

With rapid and efficient drug release, few side effects and excellent biodegradable properties, the reduction-sensitive carriers is not only the new hot point in the field of pharmaceutical research, but also the most promising intelligent drug carrier on clinical application. This paper reviews the latest research of reduction-sensitive drug and gene carriers, including the mechanisms of drug release and the synthesis of the reduction-sensitive conjugates, reduction-sensitive nano polymer micelles, nano vesicles, nano hollow microspheres, nano liposomes, as well as the characteristics and advantages of various kinds of carrier system. It will provide a theoretical basis for its further application.

Analysis of drug resistance and risk factors of Enterobacteriaceae in burn units / 中华烧伤杂志

<p><b>OBJECTIVE</b>To study the risk factors of infection of extended-spectrum beta-lactamases (ESBL)-producing strains and drug resistance of Enterobacteriaceae that infected burn patients.</p><p><b>METHODS</b>A retrospective study was performed on clinical information of 92 patients with Enterobacteriaceae infection in our burn unit from January 2001 to December 2008. The distribution and drug resistance of Enterobacteriaceae, and the detection rate, drug resistance of ESBL-producing strains, and its risk factors of nosocomial infection were analyzed. Data were processed with Chi-square test.</p><p><b>RESULTS</b>One hundred and nine strains of Enterobacteriaceae were isolated, with 38 (34.9%) strains of Enterobacter cloacae, 25 (22.9%) strains of Escherichia coli, 22 (20.2%) strains of Klebsiella pneumoniae, 13 (11.9%) strains of Proteus mirabilis, and 11 (10.1%) other strains of Enterobacteriaceae. Enterobacteriaceae were moderately or highly resistant to antibiotics except imipenem, resistance rate of which was less than 8.0%. ESBL-producing strains accounted for 44.0% in Escherichia coli, and 77.3% in Klebsiella pneumoniae. Drug-resistance rate of ESBL-producing strains to antibiotics was obviously higher than that of non ESBL-producing strains. Length of hospital stay longer than 20 days, and use of the third-generation cephalosporin longer than 5 days, quinolone antibiotics longer than 7 days, and topical antibiotics longer than 5 days were the risk factors of nosocomial infection caused by ESBL-producing strains, comparing with non ESBL-producing strains, the difference was statistically significant (with chi2 value respectively 5.491, 4.441, 15.186, 4.938, P values all below 0.05).</p><p><b>CONCLUSIONS</b>Enterobacteriaceae strains in burn unit of our hospital are highly drug resistant, with high lactamase-producing rates, calling for intense monitor to control the risk factors that predispose the infection of ESBL-producing strains in order to lower the infection rate.</p>

Indications, technique and efficacy of organ preserving pancreatectomy / 中华外科杂志

<p><b>OBJECTIVE</b>To discuss the proper surgical management of pancreatic benign and low-grade malignant potential neoplasm.</p><p><b>METHODS</b>The experience of 72 cases who accepted organ preserving pancreatectomy from January 1990 to May 2010 was analyzed retrospectively. There were 24 male and 48 female, aged from 15 to 68 years with mean age of 46 years. There were 9 cases underwent duodenum-preserving resection of the head of the pancreas, 29 cases underwent spleen-preserving distal pancreatectomy, 11 cases underwent middle segmental pancreatectomy, 23 cases underwent tumor extirpation of huge pancreatic cancer in pancreatic head and body.</p><p><b>RESULTS</b>Pancreatic fistula and biliary fistula in 1 case respectively were cured among who accepted duodenum-preserving resection of the head of the pancreas. Pancreatic fistula was found in 3 cases who accepted spleen-preserving distal pancreatectomy. Pancreaticobiliary anastomotic bleeding in 1 case was cured among who accepted middle segmental pancreatectomy. Pancreatic fistula was found in 5 cases among who accepted tumor extirpation of huge pancreatic cancer in pancreatic head and body, and liver metastasis was found in 3 cases at 6, 12, 16 months after surgery respectively.</p><p><b>CONCLUSIONS</b>Organ preserving pancreatectomy can obviously reduce operative injury to patients, its therapeutic effect is similar to that of classical operation, it is the first option of benign and low-grade malignant potential neoplasm.</p>

Macrocystic serous adenoma of the pancreas: a report of 5 cases / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the diagnosis and treatment of macrocystic serous adenoma of the pancreas (MSAP).</p><p><b>METHODS</b>The clinical data of 5 patients with MSAP treated from October 1999 to October 2009 were retrospectively analyzed. There were 5 female and 1 male.</p><p><b>RESULTS</b>Of the 5 patients, 3 patients presented with abdominal pain and fullness, 1 patient with jaundice, 1 patient with asymptomatic. Ultrasonography and CT could manifest macrocystic lesion of the pancreas; all the lesion showed a well-defined border, internal septations, enhanced cyst walls, with no intramural (mural) nodule and papillary projections; the wall was smooth and thin in 4 cases; irregular lobulation could be observed in 3 cases, round or oval in 2 cases; 2 cases had pancreatic duct dilatation, 1 case had biliary duct dilatation. The tumors located in the pancreatic body and tail in 3 cases, the tumors located the pancreatic head in 2 cases. The sizes of the tumors ranged from 6.5 cm to 13.0 cm (mean, 8.8 cm). Five patients all accepted surgical intervention. The main postoperative complication was pancreatic fistula (2 cases); all the fistula was cured. Recurrence or metastasis were not found in 5 patient followed up postoperatively from 8 to 35 months.</p><p><b>CONCLUSIONS</b>MSAP has no specific symptoms. The imaging appearance of MSAP is similar to mucinous cystic neoplasm of the pancreas. The tumor can gradually grow up and produce compression symptoms. MSAP can be cured by complete resection.</p>

Cloning and expression of rotavirus SA11 VP7 and preparation of IgY antibodies against recombinant VP7 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To prepare eukaryotic expression of rotavirus (RV) SA11 capsid protein VP7, and to generate and purify yolk immunoglobulin (IgY) antibodies against the recombinant VP7 from Roman hens.</p><p><b>METHODS</b>MA104 cells were infected with the standard SA11 strain and the culture fluid was collected. A DNA fragment of 978 bp encoding SA11 VP7 was obtained by RT-PCR amplification from genomic RNA of RV SA11. The PCR products were ligated to pMD18-T vector following the confirmation by DNA sequencing and sub-cloned into pPICZalphaB. The recombinant pPICZalphaB-SA11 VP7 was transformed into E coli Top10. The plasmids were linearized by digestion of BstXI and transformed into Pichia pastoris X-33 through electroporation by DNA sequencing. The transformants were induced with methanol for expression. The cultural supernatant was subjected to SDS-PAGE and Western blotting. Fusion expression was purified through the column of affinity chromatography. IgY was identified and purified by SDS-PAGE and Western blotting from eggs of Roman hens immunized with recombinant SA11 VP7.</p><p><b>RESULTS</b>The RNA extracted from the RV culture fluid consisted of 11 bands visualized by silver staining. The expression vector pPICZalphaB-SA11 VP7 was constructed and the fusion protein in Pichia pastoris X-33 was harvested and purified. The recombinant SA11 VP7 with molecular weight of 40 200 was identified by Western blotting. The IgY antibodies against the recombinant SA11 VP7 were produced with a purity of 95 percent and yield of 10.2 mg per egg.</p><p><b>CONCLUSION</b>The preparation of IgY antibodies to recombinant SA11 VP7 might lay a foundation for the development of vaccines and diagnostic techniques.</p>

Diagnosis and surgical treatment of 98 cases with adult primary retroperitoneal malignant tumor / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the diagnosis and surgical treatment of adult primary retroperitoneal malignant tumor (APRMT).</p><p><b>METHODS</b>The clinical data of 98 cases with APRMT underwent resection from January 1990 to April 2003 were analyzed retrospectively.</p><p><b>RESULTS</b>Among the 98 cases, complete excision were performed in 79 cases (80.6%), palliative excision in 16 cases (16.3%), tumor biopsy only in 3 cases (3.1%). Resection of involved adjacent organs were carried out in 25 cases (25.5%) and the re-operation rate for recurrence was 28.6% (28 cases). The 1, 3, 5 year survival rates for 79 cases with complete resection were 93.7%, 73.4% and 34.2%, respectively. The 1, 3, 5 year survival rate for 16 cases with palliative resection were 75.0%, 6.3% and 6.3%, respectively.</p><p><b>CONCLUSIONS</b>Certain imaging examinations are crucial to the diagnosis and preoperative evaluation of APRMT. Resection of the involved organs could improve resection rate and prognosis. For the recurrent cases, earlier reoperation is strongly recommended.</p>